Loom having a stop-motion mechanism

ABSTRACT

The contact elements for the warp yarns are supported on holding devices which are mounted in cantilevered fashion on a single support tube. The support tube is located upstream of the contact elements with respect to the direction of movement of the warp yarns. The holding devices at the ends of the contact elements are pivotal in order to entrain the droppers of the broken warp yarns on the contact elements and thereby locate the broken warp yarns.

United States Patent lnventor Erwin Pfarrwaller Winterthur, SwitzerlandAppl. No. 763,733

Filed Sept. 30, 1968 Patented June 15, 1971 Assignee Sulzer Brothers,Ltd.

Winterthur, Switzerland LOOM HAVING A STOP-MOTION MECHANISM 10 Claims, 3Drawing Figs.

11.8. CI 139/369 Int. Cl D03d 51/28 Field of Search 139/369, 358, 353,349; 66/163 References Cited UNlTED STATES PATENTS 3,358,718 12/1967Boger etal 139/358 951,487 3/1910 Began 139/369 1,760,967 6/1930 Shutt139/369 2,322,385 6/1943 Payne..... 139/369 2,858,857 11/1958 Picano1..139/369 3,421,552 H1969 Sotek 139/369 FOREIGN PATENTS 1,416,593 9/1965France 139/353 Primary Examiner-James Kee Chi Attorneys- Kenyon & Kenyonand Reilly, Carr & Chapin ABSTRACT: The contact elements for the warpyarns are supported on holding devices which are mounted in cantileveredfashion on a single support tube. The support tube is located upstreamof the contact elements with respect to the direction of movement of thewarp yarns. The holding devices at the ends of the contact elements arepivotal in order to entrain the droppers of the broken warp yarns on thecontact elements and thereby locate the broken warp yarns.

LOOM HAVING A STOP-MOTION MECHANISM This invention relates to a loomhaving a stop-motion mechanism. More particularly, the invention relatesto a loom having a stop-motion mechanism utilizing droppers on the warpyarns.

Looms have been known to utilize warp stop-motion mechanisms whichcontain raillike insulated electrical contact elements and stop-motiondroppers. The contact elements have been mounted in holding devices andarranged at rightangles to the warp yarns traversing the loom while thedroppers have been suspended on the warp yarns to cooperate with thecontact elements. Upon breaking of a warp yarn, such droppers becomeunsupported and thus drop down so as to actuate various circuits tocause a shutdown of the loom until the broken warp yarn is repaired.

l-leretofore, the holding devices for the contact elements have beenfixed between and to two support bars. These support bars, however, havestraddled the contact elements with respect to the direction of warpadvance. Thus, when a new warp beam with stop-motion droppers suspendedon the warp yarns has been inserted in the loom, the droppers haverequired lifting over the support bar nearer the warp beam. Therefore,it has been practically impossible to insert the stopmotion droppers andcontact elements safely in the holding devices.

Accordingly, it is an object of the invention to allow the mounting ofnew warp beams without interference from the supports of the contactelements of stop-motion mechanisms.

It is another object of the invention to facilitate the insertion ofstop-motion droppers and associated contact elements in a loom.

It is another object of the invention to eliminate lifting ofstop-motion droppers from warp yarns when changing warp beams.

It is another object of the invention to locate broken warp yarns in arapid manner after actuation of a stop-motion mechanism.

Briefly, the invention provides a loom with a holding device for aplurality of electrical contact elements which is mounted on a singlesupport disposed downstream of the contact elements with respect to thewarp yarn advance. The holding device includes a pair of outer holdingdevices and at least one intermediate holding device which serve tosupport the contact elements. The outer holding devices are in fixedrelation to the contact elements and are pivotal in the plane of thecontact elements to move the contact elements across the warp yarns. Theintermediate holding devices, on the other hand, are fixedly mounted onthe support and permit the contact elements to slide therein. Also, theintermediate holding devices serve to support a plurality of guide railsover which the warp yarns travel below the contact elements.

Thus, when the warp beam is changed the various contact elements and theassociated stop-motion droppers can be inserted one after the other intothe holding devices for the contact elements from the rear of the loomwithout lifting either the contact elements or, above all, thestop-motion droppers to any substantial extent.

The outer holding devices by pivoting permit the contact elements whichare crenellated on the upper edge to engage the stop-motion droppers ofbroken warp yarns. Theengaged droppers can then be carried along by thecontact elements for a short distance so as to cause an interruption inthe normal pattern of the droppers. This interruption thus permits arapid location of the broken warp yarns.

These and other objects and advantages of the invention will become moreapparent from the following detailed description when taken inconjunction with the accompanying drawings in which:

FIG. 1 diagrammatically illustrates a plan view of a part of a loomincorporating a contact element holder according to the invention;

FIG. 2 illustrates a view taken on line lI-II of FIG. 1; and

F IG. 3 illustrates a view taken on line Ill-Ill of FIG. 1.

Referring to FIG. 1, a central support 1 of the loom connects twouprights 2 of the loom base between which a warp beam 3 and a warpstop-motion mechanism 5 are mounted. In addition, a support beam 5 whichextends across the entire width of the loom is attached to the ends ofthe uprights 2 near the warp beam 3 and carries links 6 at the ends. Thelinks 6 serve to carry a pivot 7 on which a tension beam 8 is rotatablymounted. The tension beam 8 also extends across the width of the loom.

Referring to FIGS. 1 and 2, the support beam 5 is in the form of a tubewith a greater diameter at the ends than at the center and carriessupport arms 9, ill on each end and at the center, respectively. Eachsupport arm 9 is fixed to the ends of the support beam 5 by means ofscrews 10 (FIG. 2) while the support arm 11 (FIG. 3) is clamped to thecenter by means of a U-bolt 12 enveloping the beam 5 and a crosspiece l3cooperating with the U-bolt 12. The support arms 9, 11 are disposed toextend from the support beam 5 into the space between the uprights 2 andcarry holders 14, 15 at the free ends, respectively. The holders 14, 15serve to carry a hexagonal support tube 16 which runs parallel to thelongitudinal axis of the support beam 5. The support tube 16 in turn hasa plurality of holding devices 17, 18 fixed thereon which carry aplurality of parallel insulated electrical contact elements 19 ofraillike shape.

The contact elements 19 are fixed to the outer holding devices 17 (FIG.2) by a common crosspiece 20 which is attached to the holding device 17by means of screws 21. In addition, the contact elements 19 are slidablymounted in the intermediate holding devices 18. Each contact element 19contains two mutually insulated open mechanically connected rails whichare connected to an electrical switch device (not shown) fordeactivating the loom drive.

Referring to FIG. 2, the contact elements 19 rest inside the holdingdevices 17 on comblike bearings 22 made of insulating material, forexample, a synthetic plastic material. The bearings 22 are attached byscrews 24.- to the uprights of a U- shaped yoke 25, in such a way as tobe pivotable about an axis perpendicular to the holding elements 19. Theyoke 25 rests on a pivot 26 which is slidably displaceable in a sleeve27. The pivot 26 ends approximately in the middle of the sleeve 27 andbears on a compression spring 29 mounted in the bottom of the sleeve 27.A threaded pin 28 engages in the bottom end of the pivot 26 and projectsthrough the spring 29 and the bot tom of the sleeve 27 to carry a nut 30on the outside of the sleeve 27. The sleeve 27 is mounted on a shaft 31which is carried in a mounting 32 attached to the hexagonal tube 16. Theshaft 31 is connected to a pivot lever 33 which extends upwardly and ispivotable in a plane parallel to the contact elements 19.

Referring to FIG. 3, the contact elements 19 also rest inside theintermediate holding devices 13 on similar comblike bearings 23 whichare each attached to a bracket 38 of a hold ing device 34 by a screw 39.The bearings 23 are adjustable as to height by means of an elongatedslot 40 which receives the screw 39. The bracket 38 is mounted on thehexagonal tube 16 by means of a forked end and by means of a crosspiece41 which is disposed over the forked end and screws 42 which secure thecrosspiece 41 to the bracket 38 in clamping relation to the tube 16. Inaddition, the bracket 38 carries a plurality of guide rails 35 which aresituated on a line corresponding to the path of the warp yarns 36.

The warp yarns 36 pass from the warp beam 3 over the tension beam 8 inthe direction indicated by the arrow 37 (FIG. 2) over the top edge ofthe hexagonal tube 16 towards the healds 47, 48. The guide rails 35 arearranged so that the warp yarns 36 bear thereon in passing towards thehexagonal support tube 16.

Referring to FIG. 3, a plurality of stop-motion droppers 43 (only one ofwhich is shown for clarity) are threaded onto the contact elements 19 bymeans of eyelike apertures 44 and are suspended on the warp yarns 36 bymeans of a forked end which passes over each warp yarn 36. Additionally,the drop pers 43 are disposed between pairs of adjacent guide rails 35to be guided thereby. if a warp yarn is not broken, the dropper 43thereon is supported and guided so that the lateral arms of the eyelikeaperture as do not touch, or barely touch, the sidewalls of the contactelement 19 and the crosspiece 45 of the dropper is maintained out ofcontact with the contact element 19.

In operation, should a warp yarn break, the stop-motion dropper 83thereon drops onto the contact element 19 so that the cross-piece 45bridges the two mutually insulated rail portions making up the contactelement thereby closing a circuit and a signal is issued to stop theloom.

Since the respective holding devices 17, 18 and 34 are mounted on thehexagonal tube 16, the position of the contact elements 19 and of theguide rails 35 relative to the path of the warp yarns 36 is adjustablewith great precision. For example, with a preliminary adjustment beingcarried out when the support arms 9, 11 are attached to the support beam5, the position of the hexagonal support tube 16 and therefore theholding devices l7, l8 and 34 can then be selected according to the pathof the warp yarns 36.

The height of the holding devices 17 can be changed by turning therespective nut 30. That is, if the nut 30 is loosened the pivot 26 israised due to the expansion of the compression spring 29 in the sleeve27. If the nut 30 is removed, the whole holding device 17 can be removedfrom the sleeve 27. The contact elements 19 and their holding devices 17can therefore be inserted and removed as a single unit.

Alternatively, in one embodiment of the invention, the hexagonal tube 16with all the holding devices l7, 18, 34 attached thereon can be insertedand removed as a single unit in the loom.

In order to be able to find a broken warp quickly, the contact elements19 are provided with crenellationlike recesses along the top surfacesand the lever 33 and therefore the sleeve 27 with the holding device 17is tilted backwards and forwards. The contact elements 19 which areattached to the bearing 22 and displaceably mounted in the holdingdevices 18 are thus moved backwards and forwards in their longitudinaldirections. Since the stop-motion droppers 43 suspended on the intactwarp yarns touch the contact rails 19 in their eyes 44 only laterally,they remain in substantially the same position as before. The dropperfor the broken warp yarn, however, either catches on the associatedcontact element upon dropping or catches in one of the crenellationlikerecesses along the top of each contact element as it is displaced. Thedropper is therefore entrained by the moving contact element so as topush the adjacent droppers suspended on the intact warp yarns closertogether. The position of the broken warp yarn can therefore bedetermined immediately by the consequent interruption in the usualpattern of the droppers.

I claim:

1. in combination with a loom having a warp beam for delivering aplurality of warp yarns in a predetermined path and a plurality ofhealds, a stop-motion mechanism including a single support disposedacross the plane of the path of the warp yarns upstream of said healds,a plurality of holding devices mounted on said single support, aplurality of raillike insulated electrical contact elements mounted insaid holding devices over the path of the warp yarns in perpendicularrelation to said path at a point upstream of said single support, and aplurality of stop-motion droppers suspended on respective warp yarns,each stop-motion dropper being mounted on a respective one of saidcontact elements for dropping into said contact element in response tobreaking of the respective warp yarn.

2. The combination as set forth in claim 1 wherein said stopmotiondroppers are threaded onto said contact elements.

3. The combination as set forth in claim 2 which further comprises aplurality of raillike guide elements mounted in at least theintermediate ones of said holding devices under the path of the warpyarns in parallel relation to said contact elements for guiding the warpyarns, said droppers being disposed between adjacent airs of said guideelements.

. The combination as se forth in any of claims 1 to 3 which furthercomprises a support beam disposed upstream of said contact elements, anda pair of support arms adjustably pivotably mounted on said support beamand connected to said single support whereby said single support isadjustable relative to the path of the warp yarns.

5. The combination as set forth in any of claims 1 to 4 wherein saidcontact elements are fixedly mounted in the outer of said holdingdevices and slidably mounted in the intermediate holding devices andwhich further comprises a support member in each said outer holdingdevice fixed to said contact elements and means for moving said supportmember in a plane transverse to said contact elements whereby saidcontact elements are adjustable with respect to the warp yarns.

6. The combination as set forth in claim 5 wherein said contact elementsare pivotally fixed to said support member and recessed on the topsurface, and which further comprises means for pivoting said supportmember longitudinally in the plane of said contact elements whereby astop-motion dropper of a broken warp yarn can be entrained on therespective contact element during movement thereof.

7. The combination as set forth in claim 1 wherein said holding devicesand said contact elements are removable as a unit from said loom.

8. The combination as set forth in claim 1 having three of said holdingdevices distributed over the length of said single support.

9. The combination as set forth in claim 1 wherein the top edge of saidsingle support is positioned in the plane of the warp yarns.

10. The combination as set forth in claim 3 wherein the top edge of saidsingle support and said guide elements are in the same plane.

1. In combination with a loom having a warp beam for delivering aplurality of warp yarns in a predetermined path and a plurality ofhealds, a stop-motion mechanism including a single support disposedacross the plane of the path of the warp yarns upstream of said healds,a plurality of holding devices mounted on said single support, aplurality of raillike insulated electrical contact elements mounted insaid holding devices over the path of the warp yarns in perpendicularrelation to said path at a point upstream of said single support, and aplurality of stop-motion droppers suspended on respective warp yarns,each stop-motion dropper being mounted on a respective one of saidcontact elements for dropping into said contact element in response tobreaking of the respective warp yarn.
 2. The combination as set forth inclaim 1 wherein said stop-motion droppers are threaded onto said contactelements.
 3. The combination as set forth in claim 2 which furthercomprises a plurality of raillike guide elements mounted in at least theintermediate ones of said holding devices under the path of the warpyarns in parallel relation to said contact elements for guiding the warpyarns, said droppers being disposed between adjacent pairs of said guideelements.
 4. The combination as set forth in any of claims 1 to 3 whichfurther comprises a support beam disposed upstream of said contactelements, and a pair of support arms adjustably pivotably mounted onsaid support beam and connected to said single support whereby saidsingle support is adjustable relative to the path of the warp yarns. 5.The combination as set forth in any of claims 1 to 4 wherein saidcontact elements are fixedly mounted in the outer of said holdingdevices and slidably mounted in the intermediate holding devices andwhich further comprises a support member in each said outer holdingdevice fixed to said contact elements and means for moving said supportmember in a plane transverse to said contact elements whereby saidcontact elements are adjustable with respect to the warp yarns.
 6. Thecombination as set forth in claim 5 wherein said contact elements arepivotally fixed to said support member and recessed on the top surface,and which further comprises means for pivoting said support memberlongitudinally in the plane of said contact elements whereby astop-motion dropper of a broken warp yarn can be entrained on therespective contact element during movement thereof.
 7. The combinationas set forth in claim 1 wherein said holding devices and said contactelements are removable as a unit from said loom.
 8. The combination asset forth in claim 1 having three of said holding devices distributedover the length of said single support.
 9. The combination as set forthin claim 1 wherein the top edge of said single support is positioned inthe plane of the warp yarns.
 10. The combination as set forth in claim 3wherein the top edge of said single support and said guide elements arein the same plane.